setup: try a non-pure version of the local Mercurial if the pure fails
Things like `zstd` can make the pure version fails.
# Declare macOS-specific requirements for generating
# the compiled (frozen) set of requirements in
# ./requirements-macos.txt.
# If run on Windows, it may be necessary to run dos2unix
# on the output file to replace any CRLF newlines with LF.
# TODO: dulwich, pygit2, and pytest-vcr are flagged as being
# incompatible with in-memory resources. Maybe there's a
# way to bundle just them externally.
docutils
#dulwich
# Needed by the release note tooling
fuzzywuzzy
keyring
#pygit2
pygments
# Needed by the phabricator tests
#pytest-vcr